The present invention relates to a device for removing debris from a surface of a tape media. More particularly, it relates to an on-line or off-line tool capable of removing both loose and adherent debris from a media tape, preferably a magnetic tape, via a multi-slotted cleaning head and/or a negative pressure multi-cavity cleaning head.
Tape media, such as magnetic tape, is used for a wide variety of applications, including data storage. For data storage, servo-write applications, a very precise magnetically encoded pattern is placed on a front surface of the tape that otherwise interfaces with a magnetic or servo-writing head during use. Any debris carried by the magnetic tape (loose or more permanently adhered) can contaminate the servo-writing head, possibly disturbing a requisite spacing between the head and the tape. This, in turn, may lead to reading and/or writing errors. As such, it is highly desirable to remove as much debris as possible from the magnetic tape either during initial manufacture and/or during use. Other forms of tape media (e.g., optical tape) present similar cleaning and/or finishing concerns.
Specialized cleaning tapes have been developed that can be periodically employed to hopefully clean an otherwise contaminated head. Unfortunately, a user may forget to utilize the cleaning tape/cartridge or the cleaning tape may not effectively remove all debris. A more preferred solution is to remove debris from the magnetic tape itself prior to interaction with the head. In particular, because most unwanted debris is generated during the tape manufacturing process, a magnetic tape cleaning device is preferably implemented as part of the manufacturing process.
Currently available techniques for removing debris from magnetic tape are relatively limited and rudimentary. A first approach entails wiping the storage tape with a roughened woven or non-woven fabric. While the fabric undoubtedly removes some debris, the cleaning effects are less than complete. Alternatively, sapphire blades or scrapers are used to dislodge loose debris particles from the magnetic tape. In general terms, these sapphire-based devices are typically triangular in geometry, with each corner providing a blade-like surface(s) that scrape or abrade the magnetic tape as it wrapped about the piece. In either case, the technique is not well understood and is specifically directed toward removing loose debris only. Finally, relative to the sapphire scraper, the tool itself has been found to impart undesirable scratches or nicks onto the tape.
Conversely, some tape manufacturers employ a magnetic tape finishing process that may have some cleansing or debris removal implications. This approach of finishing magnetic tape for data storage applications entails passing the magnetic tape over an existing, but non-functioning, magnetic head. The magnetic head is selected to correspond with a particular final application, and is thus commonly referred to as a xe2x80x9cdummyxe2x80x9d head. The effectiveness, price, availability, and selection of these dummy heads are not well known. As a point of reference, it has been found that following 20-30 passes over a magnetic head, a newly manufactured data storage magnetic tape has lower output error rates, and is thus more xe2x80x9cstablexe2x80x9d. Thus, the design goal of the dummy head finishing process is to achieve a stable, low spacing and possible light asperity contact between the dummy head and the magnetic tape, but is not specifically provided to remove debris. Instead, the dummy head finishing technique attempts to impart a final xe2x80x9cfinishxe2x80x9d to the magnetic tape, whereby any attached particles/debris slightly are polished. Notably, the previously-described fabric wiping or blade scraping techniques do not seek to replicate this beneficial stabilizing effect.
Tape media, for example magnetic tape, continues to be a highly viable tool for diverse applications, including recording and retrieving data. Though the materials used for magnetic tapes continue to evolve, the available techniques for cleaning debris from the tape and/or magnetic tape finishing operations have essentially remained unchanged. Therefore, a need exists for a cleaning tool that consistently removes both loose and more permanently attached particles, and simulates multiple passes over a magnetic head to xe2x80x9cfinishxe2x80x9d or stabilize the magnetic tape itself.
One aspect of the present invention relates to a magnetic tape cleaning device comprising a head having a front. A plurality of transverse slots (e.g., substantially perpendicular to tape travel) are formed in the front of the head to define a plurality of spaced ridges. Each of the ridges has an outer surface extending between opposing transverse edges. With this configuration, the outer surfaces combine to define a curved, tape-receiving face. As a tape media is driven along the tape-receiving face in a generally perpendicular fashion relative to the transverse edges, the tape intimately contacts a leading transverse edge of at least three ridges. In particular, the so-contacted leading edge serves as a scraping or cutting surface relative to the direction of tape travel. This intimate contact effectuates removal of debris. In one preferred embodiment, the head includes at least ten of the transverse slots, each having a depth in the range of 0.005-0.02 inch. In another preferred embodiment, the outer surfaces of the ridges combine to define a uniform radius of curvature in the range of 5-20 mm.
Another aspect of the present invention relates to a method of removing debris from a tape media. The method includes providing a cleaning head having a front and a plurality of transverse slots formed in the front. The slots define a plurality of spaced ridges each having an outer surface extending between opposing transverse edges. Further, the outer surfaces combine to define a curved, tape-receiving face. The tape is driven across the face in a generally perpendicular fashion relative to the transverse edges such that a transverse chordal segment of the tape intimately contacts a leading transverse edge of at least three of the ridges with the leading edge of each ridge being defined by the direction of tape travel. This driven contact between the tape and the transverse edges results in debris being removed from the tape. In one preferred embodiment, the method of removing debris is performed within a data storage tape cartridge. In another preferred embodiment, the method of removing debris is performed as part of a magnetic tape manufacturing process.
Yet another aspect of the present invention relates to a tape media cleaning device comprising a head defined by opposing outer regions and a central region. A plurality of transverse cavities are formed in the front to define a plurality of lands in the central region. Each of the lands has an outer face extending between opposing sides, with opposing corners being formed at an intersection between the outer face and the opposing sides, respectively. Further, the head includes first and second outriggers formed at the opposing outer regions, respectively. In this regard, each of the outriggers are spaced from a corresponding, adjacent land. With the above construction, the plurality of cavities are configured to establish a sub-ambient condition as a tape is driven across the outer faces in a generally perpendicular fashion relative to the lands. As a result, the tape at least partially wraps about a leading corner of at least three of the lands, thereby effectuating removal of debris. In one preferred embodiment, the head includes at least four of the lands. In another preferred embodiment, the plurality of cavities includes opposing outer cavities separating the respective outriggers from an adjacent one of the lands, along with central cavities separating the lands and adapted to generate the intended negative pressure effect. With this in mind, each of the central cavities preferably has a depth in the range of 1-10 microns. In another preferred embodiment, the cleaning device further includes a block maintaining the head, with the block being configured to selectively dictate a tape penetration position of the head relative to a magnetic tape.
Yet another aspect of the present invention relates to a method of removing debris from a tape media. The method includes providing a cleaning head having a front defined by opposing outer regions and a central region. A plurality of transverse cavities are formed in the front to define a plurality of lands in the central region. In this regard, each of the lands has an outer face extending between opposing corners. Finally, the cleaning head defines opposing outriggers formed at the opposing outer regions, respectively. A tape is driven across the outer faces in a generally perpendicular fashion relative to the lands such that a transverse chordal segment of the magnetic tape is passed over at least three of the lands. A sub-ambient condition is established within at least three of the cavities during the step of driving the tape such that the tape at least partially wraps about a leading corner of at least three of the lands, with the leading corner of each land being defined by the direction of tape travel. In this regard, the driven contact between the tape and the leading corners about which the tape is at least partially wrapped effectuates removal of debris. In one preferred embodiment, the tape is driven in a back-and-forth fashion across the outer faces.
Another aspect of the present invention relates to a tape media cleaning system including a first cleaning device and a second cleaning device. The first cleaning device includes a first cleaning head having a front within which a plurality of transverse slots are formed to define a plurality of spaced ridges. Each of the spaced ridges has an outer surface extending between opposing transverse edges. In this regard, the outer surfaces combine to define a curved, tape-receiving face configured such that a tape driven along the tape-receiving face in a generally perpendicular fashion relative to the transverse edges intimately contacts a leading transverse edge of at least three of the ridges to effectuate removal of debris. The second cleaning device is associated with the first cleaning device and includes a second cleaning head having a front defined by opposing outer regions and a central region. A plurality of transverse cavities are formed in the front of the second cleaning head to define a plurality of lands in the central region, each having an outer face extending between opposing sides. Further, each of the lands define opposing corners at an intersection between the outer face and the opposing sides, respectively. Finally, the second cleaning head includes first and second outriggers formed at the opposing outer regions, respectively. Each of the outriggers are spaced from a corresponding, adjacent land. The construction of the second cleaning device is such that the plurality of cavities establish a sub-ambient condition as a tape is driven across the outer faces in a generally perpendicular fashion relative to the lands, such that the tape at least partially wraps about a leading corner of at least three of the lands to effectuate removal of debris. In one preferred embodiment, the cleaning system further includes a feeding mechanism configured to drive a magnetic tape across the tape-receiving face of the cleaning first head and the lands of the second cleaning head as part of a magnetic tape manufacturing process.
Yet another aspect of the present invention relates to a method of cleaning a tape media. The method includes providing a first cleaning head having a front and a plurality of transverse slots formed therein to define a plurality of spaced ridges. Each of the ridges has an outer surface extending between opposing transverse edges. Further, the outer surfaces combine to define a curved, tape-receiving face. A second cleaning head is also provided. The second cleaning head has a front defined by opposing outer regions and a central region. A plurality of transverse cavities are formed in the front to define a plurality of lands in the central region, each having an outer face extending between opposing corners. Finally, the second cleaning head includes opposing outriggers formed at the opposing outer regions, respectively. A tape is driven across the tape-receiving face of the first cleaning head in a generally perpendicular fashion relative to the transverse edges such that a transverse chordal segment of the tape intimately contacts a leading transverse edge of at least three of the ridges. Further, the tape is driven across the second cleaning head in a generally perpendicular fashion relative to the lands such that the transverse chordal segment is passed over at least three of the lands. In this regard, a sub-ambient condition is established within at least three of the cavities associated with the second cleaning head such that the tape at least partially wraps about a leading corner of the at least three lands. Finally, debris is removed from the tape via the driven contact between the magnetic tape and the leading transverse edges of the first head, as well as between the tape and the leading corner of the second head about which the tape is at least partially wrapped. In one preferred embodiment, the method includes simulating multiple passes over a magnetic head as a magnetic tape is driven across the first and second cleaning heads.